[shotwell] faces: Check for flatpak extra data

[Jens Georg <jensgeorg src gnome org>]

commit 0bfe3a4971ce31beb6dbf9405c91e37dd3ef9a67
Author: Jens Georg <mail jensge org>
Date:   Mon Mar 18 21:13:32 2019 +0100

    faces: Check for flatpak extra data

 src/AppDirs.vala | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/AppDirs.vala b/src/AppDirs.vala
index 4c4b8c58..97824577 100644
--- a/src/AppDirs.vala
+++ b/src/AppDirs.vala
@@ -349,6 +349,10 @@ class AppDirs {
     }
 
     public static File get_openface_dnn_dir() {
+        var f = File.new_for_path("/app/extra");
+        if (f.query_exists)
+            return f;
+
         return get_data_subdir("data"); //get_child("openface.nn4.small2.v1.t7");
     }
 #endif